A) y' = 20x^3-6x
б) y' = (2x*3x-(x^2+1)*3)/(9x^2) = (6x^2-3x^2-3)/(9x^2) = (3x^2-3)/(9x^2) = =(x^2-1)/(3x^2)
в) y' = 2(x-1)*cos(x^2-2x+4)
г) y' = sin(2x) +2xcos (2x)
д) y' = (3x^2)/(√(1+x^3))
e) y' 20(2+5x)^3
уравнение
f(x) = ln(x+1) - 2x
f'(x) = 1/(ln(x+1)) - 2
1/(ln(x+1)) - 2 = 0
ln(x+1) = 1/2
x+1 = √e
x=√e-1